Hydraulic brake system



July 16, 1929 I I cHARLEs 1.7215372 HYDRAULIC BRAKE sYs'rEse Filed May 21, 1927 I Patente duly 1d,, 1929;

-MA'URICE GEHAIRLES, 0F COUlR-BEVO IE, FRANCE.

HYDRAULIC BKE SYSTEM.

Application filed may 21, 1927, Serial No.

The present invention forms a companion to my co-pending application Serial No. 35,740, filed June 8, 1925, and relating to hydraulic brake systems. The object of my invention is to provide an improved mechanism for the control of the brake shoes situated within the brake drums of the wheels.

Other objects of my invention will be obvious to those skilled in the art by reference to the accompanying drawings, in which 'Fig. 1 is a front elevation of mydevice with parts in section;

Fig. 2 is a view similar to Fig. 1 of a modification; and

Fig. 3 is a view similar to Fig. .l of another modification.

In Fig. 1 the liquid is brought in through a conduit 1" and is led through pipes 32, and e and into receivers 2' and 2' which are of the double piston type, each of which is provided with a. pair of pistons a a and 0: a; respectively. Each of said pistons is con: nected to an end of its respective receiver by means of a fluid tight sylphon or bellows b.

Each piston a a a a carries a piston rod 7a,, 70 lc, and is, guided in bearings 8 s s and 8, and a pair of brake shoes 7", and f are directly pivoted thereon.

From the foregoing it will be obvious that if the pressure of the fluid arriving at 1' is increased, the bellows are compressed thereby giving a displacement to the piston rods which moves the brake shoes in contact with the brake drum 0.

The principal fe'atureof this embodiment resides in tlfe fact that the displacement of the brake shoes is accomplished ,by sliding their extremities and not by their rotation about a pivot point.

Furthermore, due to the fact that the as-' sembly produces perfect self-equilibrium, the cushions of liquid which separate the two brake shoes permit one shoe to take a longer stroke than the other if necessary due to any of the well known causes such as bad re tion or a difi'erence in wear on the brakes.

In Fig. 2 the li uid is led in through a conduit 1' and conducted by means of conduits e and c as before, into receivers i and i Receiver 2', is identical to those previously described in connection with Fig. 1 and is provided with pistons 02'. carrying piston rods is extending through bearin s s, and fluid tight bellows b. Receiver-z, is pro- 193, 207, and in France September 1, 19%.

.vided with a single piston e carrying a piston rod- 03 extending through a bearing 0, and fluid tight bellows b -,The parts in receiver 71 are arranged similarly to the construction previously-described with the exception that one end of the receiver is closed and cooperates .tained therein.

Brake shoestf'" and f are pivoted to piston rods is 0 receiver 11 *at one end. The

with the single piston'conshoe f, pivots abouta fixed stud .9 at the other end while the. shoe f is adapted to be displaced by an abutment 1 carried by the piston rod (2 of cylinder 5 at its other end.

A spring t interconnects the brake shoes f, and f, and-is of sufficient strength to 1 opposethe movementof said shoes toward the drum 0 until a high pressure has been established in receiver The arrangement is such that the pistons a are separated by only a thin sheet of operating fluid when the pressure is reduced and when the pressure of the said fluid is in-- creased suificiently to overcome the action of spring t the said thin sheet increases in volume and moves the pistons away from each other which action is augumented by the beveled edges provided on the said pie tons.as shown.

With this arrangement if a low pressure is transmitted through 1', the shoe f turns about brake drum.

When the pressure becomes suflicient to overcome the tension of spring 6, brake shoe f' is moved laterally as described in connection with Fig. 1, thus increasi the braking effort thereof on drum 0. 1 the same time shoe f pivots about the stud g and further increases the braking effort by coming into contact with. drum g and enters into contact with the In the embodiment shown in Fig. e the liquid is-led directly toa receiver asimilar to receiver 5 of Fig. 2 and provided with a piston d, piston rod (5?, bearing a", and hellows b all of which is arranged as the corresponding elements, above described m connection with Fig. 2. The variations in pressure are transmitted to the 7, by means of tremity of shoe f, is adapted to contact with abutment Z.

Brake shoe f is provided with springs W and W attached'to studs W and shoe F, with a spring -W attached toa stud W',, the said springs drawing. the said shoes away from drum 0 when the pressure in receiver i is reduced sufiiciently.

In 0 eration brake shoe 1, enters into contact with the drum 0 and is turned with it.

' B meansof the connecting link u and the pivoted studs '0 and '0, it also carryswith it the shoe f pivoted at g and comes into contact with the drum. v p

In this embodiment, the shoe f receives both the force exerted by the piston J of "receiver 21 and the turning force exerted by shoe f In each of the above described embodiments, the pressure receivers and the'partscooperating therewith are adapted tobe assembled on a suitable supporting)p-late Z dis-' shoes disposed with'n said drum, hydraulic means responsive to relatively high pressuresinterconnecting two of the extremities of said shoes, a pivoted joint-for the other extremity of one of said shoes, hydraulic means associated with the other extremityof the other shoe responsive to relatively low pressures, means for supplying said-two hydraulic means with fluid under pressure.

and means normally holding said shoes inan iinoperati've position with respect to said rum.

2. In a hydraulic brake mechanism of thetype described a brake drum, a pair of brake shoes disposed within said drum, a receiver disposed between the extremities of said shoes, a pair of pistons in 'said receiver,

shoes at their extremities, means opposing .movement of said pistons'away from each other, means for introduclng a fluid under ressure between said pistons, a pivoted oint for the other extremity of one of said shoes, hydraulic means associated with the other extremity of the other shoe responsive to pressures relatively low with respect to that required by said pair of pistons and a common conduit for supplying said receiver and said hydraulic means with a liquid under pressure.

3. In a hydraulic brake mechanism of the type described a brake drum, a pair of brake shoes .disposed within said drum, a receiver disposed between the extremities of said shoes, a pair of istons in said receiver, means for connectmg said pistons to said shoes at their extremities, means opposing movement of said pistons away from each other, means for introducinga fluid under pressure between said pistons, a pivoted joint for the other extremity of one of said shoes, a second receiver disposed opposite the other, extremity of the other shoe, a piston in said second receiver, a plunger on said piston adapted to abut the extremity of said last mentioned shoe and a common conduit for supplying .said cylinders with a 1i uid under pressure.

means for connecting said pistons to said n testimony that I claim the foregoing I as myinvention, I have signed my name hereto. 1

. MAURICE CHARLES. 

